im really sorry to tell you this but i dont think she loves you, she used you to make her pain easier after her previous relationship failed. i think you should either try to move on and find somone who does want a relationship with you or if you really love and dont want to move on give her space and let her sort out her problems. if she has sorted out her issues and she still wants and relationship with you, then you should start to build up a relationship

BUT.... only after she has truly sorted out her problems else you might get hurt

You dated her for 4 months. She was with another guy for 2 years. You were definitely a rebound relationship and it didn't work for her. Leave her be. She likes you but she doesn't love you in the romantic way that you want and derserve. She loves her ex bf still. A longterm 2 year relationship takes time to heal from. In all fairness to you--as hard as it is, she didthe right thing, rather than stringing you alone. I respect her decision to do this. You now have the freedom to pursue other opportunities but please...wait, until you are emotionally healed and over your feelings for her. You don't want to begin dating someone yourself, on the rebound, either. The only way to getting over this gf of yours..is by following the 'no contact' rule. Texting her will increase her frustration and she will eventually really resent you.

You are hurting but over time you will gain a few lessons about dating people who are on the rebound. Try hard to not allow this to happen, again. So no more contact with her, you need do some healing and recovery, too. Keep your self-respect intact and realize, there is happiness and an enriched life, after this girl. You just have to get out there and find it. There are many super girls out there who would appreciate you. Just choose wisely, in the future. Good luck my dear and keep being strong.

This is the advice from someone who's been there. And, I am a man; not that the other poster's advice is wrong, but, it reflects THEIR side of the story.

Listen carefully: If she asks you for space, you're doomed. Move on. Resist the temptation to call her or text her. In fact, resist any temptation to contact her in any way. If you need to get a straitjacket for this, have some friends do you that huge favor. Nobody will understand your pain; people will only find you pushy and immature

Don't contact her, in any way. If she came back, which I seriously doubt, don't take her. If she left you, there were issues, and it's only very likely you'll make the same mistakes again. It's time for you to move on.

Wish I had advice that could get her back for you, but I don't. It's possible that when she's done with this "time to herself" she'll be ready to move on with you. But I wouldn't count on it, because it's not likely.

Give her the space she's asked for. Ask her for "coffee" and non-committal things like that to keep in the game. But DON'T get all in a huff if you hear that she's going someplace without you. It will cause her to push you completely away.

In the mean time, go on dates with other people. Don't pine for her. Do things that give you confidence in yourself (self-confidence is sexy). Knowing that she hasn't crushed you may make her able to keep you in her life. But be ready to move on.

Let her go, she is on the rebound anyway, and needs time to heal from her last relationship....you are young, too young not to enjoy being single, have fun and be with whom ever you want and get out of the house to do things with your friends, best cure ever for a broken heart.